I don't think that people who say they split meals would suggest this for people with teenage boys or a big DH??? We split meals at Disney (and when we go out at home) almost every meal. However I am a light eater and have 2 teen GIRLS who are light eaters. I would also say that my DH is a light eater for a guy. He routinely gets entree salads as his meal. But I rarely share with him.
Also, I don't think its fair to split a salad and then question where all the places are at Disney where you can share. I have never once read on a sharing thread about people splitting a salad??

People suggest splitting the ribs/chicken meal at Cosmic Rays and things like that.
On the "buy an extra bun and split a double cheeseburger" situation, I would say in most instances people who suggest that were talking about little kids, not teen boys.
Here are a few of the meals that we have shared:
Steak and shrimp meal at Yak and Yeti
Chicken meal at Whispering Canyon Cafe (this is NOT the all you can eat skillet)
Steak and shrimp and rib meal at Rainforest Cafe
Chicken and rib meal at Cosmic Rays
Chicken parmesan meal at Mama Melrose
Nachos at ESPN Zone
Steak sandwich at Beaches and Cream so we could have a little room for one of the sundaes
Your family might not be one that can use this savings technique due to the makeup of the family. Just like my family can't take advantage of any savings the Dining Plan would offer. Not everyone can use all the "tips".
If I had teen boys and a big DH, I would definitely get the dining plan and eat our TS meals at buffets. I think that would be your best bet.
Maggie